In polling of our players, here’s what they had to say:

26% of All Players Adjusted Immediately
37% of All Players Adjusted Within 1 Week
63% of All Players Adjusted Within 1-3 Weeks
81% of All Players Adjusted Within 4-6 Weeks

So as you can see, some are quicker and some take a bit of time. But the overall trend suggests everyone can adjust to single length irons and start realizing the consistency benefits within just a couple months.